In previously available storage systems data mirroring has been used to provide fault tolerance. With data mirroring, multiple copies of an object are stored on a vault disk (or other storage mediums) and again on different disks, so that an individual disk failure damages or results in the loss of merely one copy of the data. A downside of data mirroring is that it relies on significantly increasing memory utilization for each degree of fault tolerance. For example, in order to provide resilience for one disk failure, twice as much disk space is utilized. In order to provide resilience for two disk failures, three times the disk space is utilized. Another problem with data mirroring is that it would result in a policy conflict for recording various media programs, by cable and other media delivery service providers. Specifically, when recording a program on behalf of a customer, the Digital Millennium Copyright Act (DMCA) enacted on Oct. 28, 1998, provides that one and only one unique instance of the data may be created for the customer. In this context, data mirroring for the sake of providing fault tolerance violates copyright and associated fair use restrictions.
Additionally, implementation of modern large-scale data storage techniques is preferred, to allow for fast, reliable writing of large volumes of fault-tolerant data. Write operations requested by a client have a time limit for completion. However, in some instances the data set associated with a request for a write operation is very large, and the write operation cannot be completed within a time limit for completion if several smaller write operations are received and scheduled by a storage system in advance of the larger data set.
In accordance with common practice the various features illustrated in the drawings may not be drawn to scale. Accordingly, the dimensions of the various features may be arbitrarily expanded or reduced for clarity. In addition, some of the drawings may not depict all of the components of a given system, method or device. Finally, like reference numerals may be used to denote like features throughout the specification and figures.